Bug#819826: steam: libstdc++ check extremely expensive

[Kevin Gillette]

Package: steam
Version: 1.0.0.51-1
Severity: normal

Dear Maintainer,

   * What led up to the situation?

Steam takes a rather long time to start. "Steam App" (game) load time
may also be subsequently affected, depending on available memory (VFS
cache).

Inside of the "/usr/games/steam" shell script are the lines:

  # remove steam-runtime's libstdc++ files, which are incompatible with
  # newer mesa drivers (https://bugs.freedesktop.org/78242)
  find $config -name libstdc++.so.6\* -execdir rm -f {} \;

Here, $config is "$HOME/.steam", which contains all installed files
for all installed games. Scanning that many directories may be rather
slow on a cold VFS cache for some filesystems. If the pertinent *.so
files are present in only a select few directories, those should be the
directories explicitly passed to find. Alternatively, we may be able to
forego the check entirely and use some kind of LD_PRELOAD solution. Or
we can provide this as bundled script that users can run if needed.

Commenting out the "find" line shaved minutes of processing spent
looking for this edge-case.

   * What exactly did you do (or not do) that was effective (or
     ineffective)?

Start Steam with ~600 GiB of installed games.

   * What was the outcome of this action?

5+ minutes delay before windows are drawn (compared to less than 3
seconds with the check disabled).

   * What outcome did you expect instead?

Quick startup time.

-- System Information:
Debian Release: stretch/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (500, 'testing'), (500, 'stable'),
(1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.4.0-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968)
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)

Versions of packages steam depends on:
ii  debconf [debconf-2.0]             1.5.59
ii  libc6                             2.22-5
ii  libgl1-mesa-dri                   11.1.2-1
ii  libgl1-mesa-glx                   11.1.2-1
ii  libstdc++6                        5.3.1-13
ii  libtxc-dxtn-s2tc0 [libtxc-dxtn0]  0~git20131104-1.1
ii  libudev1                          229-3
ii  libx11-6                          2:1.6.3-1
ii  libxinerama1                      2:1.1.3-1+b1
ii  xz-utils                          5.1.1alpha+20120614-2.1

Versions of packages steam recommends:
ii  fonts-liberation                         1.07.4-1
ii  rxvt-unicode-lite [x-terminal-emulator]  9.21-1+b1
ii  stterm [x-terminal-emulator]             0.5+20140606+gitc2fd275-1
ii  xterm [x-terminal-emulator]              324-1
ii  zenity                                   3.18.1.1-1

Versions of packages steam suggests:
pn  steam-devices  <none>

-- debconf information excluded